The present invention relates to a slide valve for containers with upright supply of bulk materials.
Slide valves of the above mentioned general type are known in the art. A known slide valve has a deflecting cone arranged coaxially to an inlet opening of a container, and a pneumatically displaceable tubular slider which in open position releases an annular inlet gap and in closed position abuts with its upper edge against a sealing face which is protected from flow of the bulk material. A tubular valve which uses this principle is known from the German Pat. No. 1,675,371. In the first mentioned construction, the deflecting cone is arranged on supporting members in standing position on the upper connecting flange of a tube which opens into a container with bulk material and serves as shield guide for the tubular slider connected with the piston rod of a cylinder-and-piston unit which is arranged in a tubular extension of the deflecting cone. The upper edge of the tubular slider in its open position is substantially flush with the connecting flange, which can be connected, for example, with an outlet flange of a feeding funnel. For closing, the tubular slider is displaced upwardly until its upper edge abuts against a sealing face provided above the lower edge of the tubular extension of the deflecting cone and protected from the bulk material. This construction has the advantage that the flow of bulk material is reliably closed. The disadvantage of this construction, however, is that the sliding valve is arranged completely outside of the container for which it is provided and a simple connection of an incoming supply conduit is not possible. Instead, a special feeding funnel or an intermediate container with funnel-shaped outlet must be utilized. Since the subsequently arranged container with closed sliding valve is often under pressure, there is another disadvantage of the known construction in the fact that at least two pressure-tight seals are required, namely the seal for the upper edge of the tubular slider and the seal or seals between the outer surface of the tubular slider and a tube serving to guide the latter. It is further unsatisfactory that the tubular slider in the container under pressure opens unintentionally, namely when the cylinder-and-piston unit is untight or its control medium, generally pressure air, drops.